Portable optical illumination systems selectively provide a region of illumination or optical output that may be used for a variety of purposes. The illuminated region may include various forms of visual or non-visual light for various tasks such as manual operation and/or position designation. For example, a headlamp is a portable optical illumination system designed to be worn on a user's head and is configured to visibly illuminate a selected region in front of the user for manual purposes such as walking or reading at night. Likewise, a flashlight is a handheld portable optical illumination system which optically illuminates a region to enable a user to visualize items within the region. Both headlamps and flashlights are sized to be portable to allow users to bring them to a variety of locations without adding undue weight or size.
Portable optical illumination systems include a switching mechanism to allow a user to selectively activate the illumination source. For example, electrical-based systems include a switching mechanism that selectively connects the electrical pathway between an electrical power source such as a battery, and an electrical optical output device such as a light emitting diode. One type of electrical switching mechanism utilized on conventional portable illumination system is rotationally oriented in that the manual operation of the electrical switch includes a rotational movement to selectively activate the illumination system. For example, rotational switching mechanisms may incorporate a rotational movement between two portions of the external housing of the portable optical illumination system. The rotational movement may be transverse to the optical illumination path to enable a user to selectively illuminate a region without physically obscuring optical output during the switching operation.
Conventional rotational switching mechanisms are limited in their operation. For example, the rotational switching mechanism commonly incorporated on most cylindrical flashlight type products utilizes a clockwise activation and counter-clockwise deactivation between a distal housing portion and the remainder of the system. Unfortunately, the same clockwise and clockwise-counter movements are often utilized to remove the distal-most housing portion from the system to enable access and/or replacement of the illumination output device and/or electrical power source. Therefore, a user may unintentionally disengage the distal most portion from the system while intending to merely deactivate the switching mechanism. In addition, most rotational switching mechanisms provide limited feedback to the user during operation, thereby forcing the user to rely on the illumination output as the only feedback. For example, a user may intuitively rotate the distal-most housing portion clockwise relative to the remainder of the system until the illumination output is activated. Likewise, the user may rotate the distal-most housing portion counter-clockwise relative to the remainder of the system until the illumination output is deactivated. This type of output-based feedback is unreliable and may cause unintended switching and/or disassembly of the system.
Further, the internal electrical configuration limits the switching functionality for the operation of the overall illumination system. In general, conventional rotational switching mechanisms require the distal-most housing to be screwed/rotated toward the remainder of the system (usually clockwise) so as to electrically engage/contact respective conductive members. The electrical engagement enables electrical current from the electrical power source to be transmitted to the optical output device, thereby activating the system. However, this electrical configuration is significantly limited to unidirectional rotational operation and single-activated-mode operation. A user may only electrically activate/switch the system in one direction so as to coincide with mechanically translating the distal most housing portion toward the remainder of the system. Single mode operation means that the switching mechanism is limited to a single on-off type mechanism or limited multi-mode operational functionality. For example, a unidirectional multi-mode system may always require a user to rotate clockwise to switch between modes 2 and 3. Likewise, a unidirectional multi-mode system may prevent single step switching between certain modes.
There is a need in the industry for rotational switching mechanisms that overcome these limitations to provide improved performance, reliability, and functionality to portable illumination systems.